Modern aircraft engine flight deck displays typically include computer-driven display screens dedicated to presenting engine status information. These display screens typically present to the pilots engine data indicating the values of a variety of engine operating parameters. For example, the display screens can present a primary engine display (shown in FIG. 1) and a secondary engine display (shown in FIG. 2).
The primary engine display can present top-level engine parameter data, such as exhaust pressure ratio (EPR) display 30, fan speed (N1) display 32, and exhaust gas temperature (EGT) display 34. The primary engine display can include multiple sets of displays (two are shown in FIG. 1), one set for each engine of the aircraft.
The secondary engine display can include information corresponding to other engine operating parameters. For example, the secondary engine display shown in FIG. 2 can include turbine shaft rotation speed (N2) display 36, fuel flow display 38, oil pressure display 40, oil temperature display 42, oil quantity display 44, and engine vibration display 46.
One characteristic associated with the foregoing approaches for displaying engine data is that the pilot or other crew member operating the aircraft must be able to quickly and easily monitor/view the data, integrate and interpret the data, and determine whether the data warrant crew awareness or action. If action is required, in many cases, the pilot must determine what action is most appropriate for the circumstances.
The primary crew tasks are to aviate, navigate, and communicate. Airplane system-related monitoring, detection and interpretation tasks should be minimized. The airplane system interface must be simple and salient. During engine start or recovery from a subidle condition, the crew must monitor, detect and interpret for engine start or recovery progress (e.g., recovering/not recovering), automation modes and sub-modes (e.g., automatic, semi-automatic, autostart, autorelight, accommodating for various non-normal conditions), and engine state (e.g., flameout, subidle, motoring, running). Currently, no explicit or easy means is provided to aid the crew in determining automation modes and submodes, if engine start/recovery is progressing normally, or how long start/recovery will likely take. The resulting crew monitoring, detection, and interpretation tasks introduce crew workload and error potential. The crew may inappropriately interrupt and delay, or terminate engine start. Conversely the crew may not, when necessary, intervene in a timely manner. Under some circumstances the pilot may need to monitor and interpret whether an engine start is progressing using whatever data/information is available.
Ways to provide new information within the context of the existing engine indication paradigm must be found and developed. The present invention provides new starting information to supplement the existing engine indication paradigm. During engine start or recovery from a subidle condition, the crew must currently monitor, detect, and interpret engine parameter indication changes to determine if engine start/recovery is progressing acceptably, estimate how long engine start/recovery will likely take, and determine when the engine is running. Monitoring and detection tasks increase crew workload and divert crew attention away from the primary task of flying and navigating the aircraft. Primary crew responsibilities, increasing levels and sophistication of engine automation designed to optimize engine start/recovery/operation, the broad range of possible operating conditions and circumstances, and the lack of explicit collocated engine automation and state indications, make correct/accurate crew interpretation of engine indications sometimes difficult.
Prior solutions involve crew monitoring, detection, interpretation, or integration tasks. In addition, no explicit engine parameter indication of target idle running speed or engine subidle/running state has been provided. The target idle running speed is the core engine speed below which the engine is considered subidle. The target idle running speed is the core engine speed at and above which the engine is considered running, can accept electrical and other loads, and can generate useful crew controllable thrust. This parameter value varies as a function of altitude, temperature and other factors such as engine make and model. Consequently, the crew must know, recall and typically estimate the engine parameter value at which the engine will be running, and/or divert time and effort to verify that the engine is running—often in a high workload or time critical situation.
There is a need for a system and a method for implementing explicit, reliable and meaningful engine start/recovery information/indications that support crew decision-making throughout the range of engine start/recovery regimes and possible engine malfunctions/abnormalities.